diff --git a/10-seq-hacking/vector_v5.py b/10-seq-hacking/vector_v5.py
@@ -268,7 +268,13 @@ def angle(self, n):  # <2>
    def angles(self):  # <3>
        return (self.angle(n) for n in range(1, len(self)))

    def __format__(self, fmt_spec=''):
        if fmt_spec.endswith('h'):  # hyperspherical coordinates
            fmt_spec = fmt_spec[:-1]
            coords = itertools.chain([abs(self)],
@@ -277,7 +283,14 @@ def __format__(self, fmt_spec=''):
        else:
            coords = self
            outer_fmt = '({})'  # <6>
-        components = (format(c, fmt_spec) for c in coords)  # <7>
        return outer_fmt.format(', '.join(components))  # <8>

    @classmethod